Piston lubricating means



Jam 12, 1954 E. w. PATTERSON 2,665,774

PIsToN LUBRICATING MEANSv Filed June 27. 1949 lNVENToR.

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l-latented ian.

PISTON LUBRICATING MEANS Edgar W. Patterson, Downey, Calif.

Application June 27, 1949, Serial No. 101,619

(Cl. 18d- 18) 8 Claims.

This invention relates to pistons within cylinders and means foreiectively lubricating and sealing pistons with reference to thecylinder bore, and particularly pertains to piston lubrieating means.

This invention is specically adapted and is of great importance inconnection with airbalanced oil well pumping units of the general typeas that shown in my recent Patent No. 2,464,710, issued March 15, 1949,and in various other types of air cylinders.

In all arrangements whereby the cylinder is iitted with a partial heador cover at the lower end theerof, there must consequently be a con*tinuous displacement of air both into and out of `the lower oratmospheric pressure end of the cylinder. This condition holds true asregards the above mentioned patent and all similar arrangements. Thecontinuous taking in of new air at each stroke of the cylinder will,under certain operating conditions, give trouble and cause unnecessarywear on the piston, rings, and cylinder walls, when the machine isoperating in the open oil fields where there is considerable dust andsand present in the atmosphere. As a matter of fact the oil contained inthe annulus acts as a trap for dust entering the chamber, andconsequently there is a continuous accumulating of dust and foreignmatter within the oil supply reservoir at all times. It is therefore theprincipal object of the present invention to provide a cylinder, piston,and means for lubricating same, wherein there will be no displacement ofair below the piston within the cylinder, and to provide an oilreservoir that is not subject to contamination from the atmosphere.

Other objects and advantages` of the invention will be apparent from thefollowing description and claims, the novelty consisting of the featuresof construction, combination of parts,

the unique relations of the members and the rela.. tive proportioning,disposition, and operation thereof, all more completely outlined hereinand particularly pointed out in the appended claims.

The invention is illustrated by way of example in the accompanyingdrawing in which:

Figure 1 is a View in side elevation, with prime mover broken away, ofan air-balanced pumping unit embodying the present invention.

Fig. 2 is an enlarged axial vertical View in elevation taken along theline 2-2 of Fig. 1.

Fig. 3 is a transverse sectional view through the cylinder and pistontaken in the plane of line 3-3 of Fig. 2.

Fig. 4 is an enlarged vertical sectional View through the oil pump takenalong line 4--4 of Fig. 2.

Fig. 5 is a transverse sectional view as seen on the line 5-5 of Fig. 4.

Fig. 6 is an enlarged fragmentary sectional View in detail of one sideof the lower part of the piston as shown in Fig. 2, showing more clearlythe oil scraper rings.

As seen particularly in Fig. 1, there is provided a pumping unitsupported jointly by a generally horizontal base Ill, and an identicalpair of vertically positioned parallel members Il dis posed at oppositesides thereof. The individual members I I are joined together bysuitable bracing to form what is known as a Samson post, which ismaintained in its vertical position by means of a pair of `angularstruts or braces l2. These braces have their ends secured respectivelynear the top of the upright members II and adjacent to the horizontalbase Ii), and are aixed at the latter point to a geared set back crankmechanism I3. The lower end of the Samson post II is in turn attached tothe main base II) by suitable hinge pins I4.

The conventional walking beam I5 is pivotally` secured at one end to thetop` of the Samson` post II by means of a shaft I6 and carries at its`vopposite end a horse-head Il over which the:

reins It! attached to a pump rod will operate.

An air receiver or tank I8 is located adjacent;

the Samson post upon the main base I0. Ro

tatably journaled in a conventional gear unit 29 is; a low speed maindrive shaft 2|, to each end of.' which is fixed a crank 22, one at eachside of the'- gear unit. The shaft 2| is suitably connected to a` lpowerunit by suitable conventional driving:

means not shown in detail.

A cylindrical air-balance cylinder 23 is pivotally supported at its topby a universal mounting from a cross-head assembly 24 axed to the underside of the walking beam I5, the balance cylinder being thus adapted toreciprocate vertically over a stationary piston 25 supported within thecylinder 23 by means of a vertically disposed tubular piston rod member2S, which in turn is pivotally mounted at its lower end in bearings 2'!carried upon the base I0. The upper end of the hollow piston rod 26communicates with the compression space 28 above the piston 25 withinthe cylinder 23, and the lower end of the hollow piston rod 26communicates with the air receiver I 9 through the pivotal base 29 andthe air duct 30.

A pair of vvertically swinging pitman rods 3| are `pivota'lly secured tocross-head member 24 `way. of pressure line 49. '.IVhere'isganannul ggrepen spaceg inlinedlately,belovi` the z upper partei piston 25andabove'ihe retrait .there- ..of. :This gap orannuluswillpermitairnnder f bracket wafforzthe Quin Y the stroke length-pf: the.-Ql .puma 39. ,as @result oil from the wall,oirthegcylmdergz l it vtoenter reservoirea by@,m e; 1s oslmalble` "sraperrines :141 and: drainagerents 56 Keem-lv` inunioatingv withgside L:Wall vents; lgleadingptofreservoir138- at their upper ends, and are attached by a journaledcrank pin 32 to the crank arms 22 at their lower ends.

Fxedly secured to the piston tube 26 is a suitable mounting bracket 34upon which is mounted the piston rod 35 of an air compressor 36, whichin turn is attached to the main cylinder head 33 and adapted toreciprocate simultaneously with the main balance cylinder for use as asource of supply for: compressedrair duringy normal operation of thepumping` unit.

As here illustrated, the main piston 25 is mounted upon the upper end ofthe hollow piston rod 26, and consists generallyora cylindrical casting,or fabricated member which'is divided into an upper reservoirShandfuaylolllr reservoir 38. The upper reservqirlis Ytheil retainingreservoir which is supplied with -oil at regular intervals by means ofan oil rpurnp`39 supported upon bracketxAO affixed to piston tube 26.Theoil carried vinreservoir 31 isadapted to l'ubricate and seal thepiston 25 within the cyl- .der 2,3.by meansbf .drilled holesiltthroughfthe circumferential walls 42,91?-therpiston.25 lead ing lto.yvan annular, grooves. 43 .therearound. The

lower reservoir f 38 Of the piston 251s adapted Uto. ,traps any oilthatmay., bypass. the upper part,

or compression partjo'f'piston. ,Thefupper g piston ringsl or packing.rings...4r4 for `.vvitltiblrlingv4 air p `or oil vunderpressure.,abovethepstonl. V.The lower partofthe piston- 25.`is`f,proylded .witha y circumferential sidwall 45 Y having.. grooves ,4,6

into whichvare ttedpistoniings ,A1.,thatare adaptedpto scrapeoiliromfthecylinder wa11. 23

pump .31,by

39. and .thence returned to` upper reservo pressure that mayrbypassthefconiprwss'ion.ring

and esepe t0- the rfatmosphere by lmeans.-.f-.vent

tube :511. through ibex-lower headtoifpiston .2,5. Y Therefisamanuallvadiustable sontactmembei. warranted tol iheouteracrlineer vanbrine Qi rredeterminine L er any.y change beineamadeas :reeardsthepumpvling strokeoi the puinpineunitl The-.Q11 Pump. `.as illustrated .inFie-z: i,` is 0f .the simple :piston displacement type emr 1oyr-1g.V'van iaintakespring 55 adapted to.returrrthenistonfffstoits uppermostposition. 1t is to be understood how- `ever,v that any.. type; pump.located at; arly-S .liable place about the pumping unit marchegiegtively, employed Without. departingn the; teachings ..herein.

Fig. 6 vshows in detail one: method forscranins 11d causing @In ordertoKV establish theglevel.oi the accubular shaft 26 and isheldpermanently ata:y delubricating and sealing method is predicated uponthe assumption that any oil that has been placed in reservoir 31 thatmay bypass the upper part of piston 25 will be entrapped in the 5 lowerreservoir 38, from which it will be directed to a pump 39 and thencereturned under pres sure to reservoir 31 from where it came without anyappreciable escapement olf oil externally of the system, orcontamination from the atmos- .phera Y In operation ofthe presentinvventilonvit will be understood that the cylinder 23 is held to theacross-head 24 by some suitable pivotal means, ``such foi-errarnple as abolt receiving bore 60 'formedin ear means mounted on the closed endkgi-cylinderzg The -cylinder 23 can oscillate as yit reciprocates uponthe oscillating piston 25. lThe reservoir -31Lbf the piston 25 may thenbe filled-Eto va desired level with lubricating oil, and the limit ofthis level may be determined by adjustingy the, tube 58. `As the pumpoperates the Ypist'ofn 25v will' relciprocatewthin the cylinder 2k3endet that time lubricating *oil'fvvilly pass vout through, the: ductsA4 I *and* the vanrnllar Y groove 43 to lubricate the cylinder. Thepiston' ringer lwill tend tok prevent leakage of lubricating bil. If,however, lubricating oil s houldfrnove p ast the Vpiston ringsiit williiqwiinto the reservoiry 38. Attention .isdirected to thevfavcthtl'iatfthe"'res'ei 3o Ivoir 38 isl atatrno'spheric pressures()vthat the lubricating oil will bev reeto flow 'downwardly talong ,thewalls of the cylinder.` YThe members ,41 in thereservoir,33',will.tendtol s crapeoff the nexcess oil and divert itinwardly'throughthe ducts 56 to thereservoir 3S,` '.Anyexcessof vthisoil will :be drawn throughvthe pipe vtolfthe valve filbithepumpstructure, `and as the cylinder I23 movesdownwardly the member 52 will'strike the'piston rod head1h35 and. force oiloutwardly c ,throughYthe'*discl'iarge lvalvejflto theY pipe"49. -The lubricating' oil will,then'dldw upwardlyin the pipe `A49,through.the reservoirs 3 8 and 31and will @be discharged f into v the x reservoir' 31, 'thus .Qmpletlgthff'yleg 45 .It Vwill` thus bey seen .thatby lizhisirneansit. isfr,possible .to automatically 'replenish Vthe j lllblcatging oil.on thepstonifandcause itto fcir'culate she-'pump functions? c, vVifhile'IQhave shown .the preferredorm .of my invention asnow known tome, it`wllbefunder- .stood that vari'ous'chan'g'esinaybe made in ,com-

bination, construction and 'arrangement,y of parts by ,thoseslrilledintheartQwithout departing `irointl'ie spirit.L of. the invention .asVclairneol.v l ,Having thus aescnbedmy; .,irivejnti, ngwhat, I claim anddesireto secure K`by 'Letters Patentv is: 1.7.-,In an airdbalance 4foraiwellipumpingunit having `a:basefavnd a walling beam mounted thereonfor vertical. `Ym.vement .and from, which `asuclzer vvredis suspended inthe ywellfthe combirra-tiony of amcylinder, s oneend .of *whichd isclosed andthe other end of which is open, said c gvlinderallarme meansfor, eivoially Connetiing vit Vclosed end to said. beam, with`itsother'hend opening downwardly; Y a piston Vvslideable in saidcylinderv and forming a reseryoirior` oil, there beingupassagemeansforIoil'to flow furomsaid .reservoir tothe Ameeting faces oi'saidpiston andsaid cylinder Ato -lubricate said -faces "a piston Y 0roduunited withsaid piston, said`rod extending downwardly `out of said cylinder.r andhaving means for. pivotallylmounting Saidfrod on fsaid basey'means foradmittingair underl high pressure to the interior of `said cylinderabovejfsaid acaban the pressure of said air; an oil collector carried onsaid rod below said piston and tting said cylinder walls closely toscrape from the latter oil escaping downward past said piston when saidcylinder reciprocates with respect to said piston and said collector; apump mounted on a lower portion of said piston rod; an actuator carriedby said cylinder and engaging said pump to actuate the same; a suctionline connecting said oil collector with the suction side of said pump,and a discharge line leading from the discharge side of said pump andopening into said oil reservoir, whereby actuation of said pump willwithdraw oil from said oil collector and discharge the same into saidoil reservoir.

2. A combination as in claim 1 in which said oil collector makes asubstantially airtight engagement with said cylinder wall; and an airbleeder tube communicating between the space between said piston andsaid oil collector and the air at atmospheric pressure below saidcollector.

3. A combination as in claim 1 in which said oil collector comprises asecondary piston providing an oil collecting basin therein and havingoil scraping piston rings, said secondary piston being provided withpassageways leading from said piston rings to said basin.

4. In an air balance, the combination of a cylinder, one end of which isclosed and the other end of which is open; a piston rod; a piston onsaid piston rod and adapted to slide within said cylinder with thelatter in upright position with its open end disposed downwardly, saidair balance being adapted to operate with said cylinder and piston thusdisposed so as to result in sliding reciprocatory vertical relativemovement between said cylinder and said piston; means for admitting airunder high pressure to the interior of said cylinder above said piston,said piston forming a reservoir for oil, the latter being subjected tothe pressure of said air in said cylinder, there being passage meansthrough which oil may ow from said reservoir to the space between saidpiston and said cylinder, a certain portion of said oil escapingdownwardly from between said piston and said cylinder incidental to saidreciprocation and said air pressure; an oil collector carried on saidrod below said piston and fitting said cylinder closely to scrape fromthe latter said escaping oil, said collector providing a basin in whichsaid oil collects and pump means for returning said escaped oil fromsaid collector basin to said piston reservoir.

5. A combination as in claim 4 in which said collector has asubstantially air tight sliding t with said said cylinder, there being ableeder passage in said collector communicating between the spacebetween said piston and said collector and the space below saidcollector.

6. A combination as in claim 4 in which said oil pump is disposedoutside said cylinder and is actuated in response to the aforesaidrelative vertical movement between said cylinder and said piston.

7. In combination: a cylinder one end of which is closed; a piston rod;a piston on said piston rod closely fitting and slideable reciprocablywithin said cylinder against a uid pressure head in said closed end ofsaid cylinder; means in said piston for supplying a lubricant to thespace between said piston and said cylinder, certain portions of saidlubricant thus supplied leaking past said piston due to the fluidpressure head against which said piston operates; oil recovery meansmounted on said piston in spaced relation with the end of said pistonfrom which said lubricantI leakage occurs, for recovering from the wallsof said cylinder the excess of lubricant leaking past said piston; andmeans for returning said recovered lubricant to said lubricant supplymeans in said piston.

8. A combination as in claim '7 in which said lubricant recovery meansclosely ts said cylinder to scrape said lubricant from said cylinder inrecovering the same; and means providing for the escape of fluid fromthe space between said piston and said lubricant recovery means tomaintain a fluid pressure in said space which is not substantiallyhigher than the iiuid pressure in said cylinder on the opposite side ofsaid lubricant recovery means from said space.

EDGAR W. PATTERSON.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 414,777 Morison Nov. 12, 1889 445,110 Graham Jan. 20, 18912,035,450 Barnes Mar. 31, 1936

